Air-filter machine



Dec. 16, 1952 D, H. GRAY, JR

AIR FILTER MACHINE Filed April 20. 1948 INVENTOR. DALLAS H. GRAY JR. BY

ATTORNEY.

Patented Dec. 16, 1952 UNITED STATES PATENT OFFICE 2,621,755 AIR-FILTER MACHINE Dallas H. Gray, Jr., oaklana calir.

Application April 20, 1948, Serial No. 22,103

6 Claims. 1

, This invention relates to air filtration and more particularly to an air filtering machine of a type adapted for use in restaurant kitchens where it is desirable to evacuate the warm grease-laden air resulting from the cooking operations.

The present invention embodies an improved air filtering machine of the kind characterized, capable of evacuating the hot grease-laden air from an area above the cooking range of a restaurant, and which at the same time functions to remove the grease from the evacuated air so it does not enter the suction blower or collect on the sides of the outlet flue to present a fire hazard. My invention utilizes the principles of filtration and ventilation, combining in a single unit adapted for installation in a range hood, a suction blower for withdrawing grease-laden hot air from the hood and an air filter for removing the grease'from the withdrawn air. The present invention also contemplates the provision of a collector associated with the air filter for receiving the particles of grease removed from the air passing through the filter. The development of deep frying equipment, griddles, masters and broilers in the past few years has created a real problem for the restaurateur due to the amount of grease that is vaporized and drawn up the stack or flue by natural or induced draft from the hood over the range. There only natural draft is utilized, the grease solidifies on any cold surface Within the kitchen area and on particularly the inside surface of the flue stack. It frequently drips onto the range or into the food cooking thereon, thereby creating an objectionable unsanitary condition. With induced draft, created by placing a suction fan or blower at the end of the kitchen stack, the grease-laden air is drawn into the hood and through the outlet stack or flue and discharged into the outer atmosphere, but the grease soon solidifies on the fan blades and clogs them up. Particularly in the case of multivane fans, the efficiency is quickly reduced and the grease-laden air is no longer expeditiously drawnout of the kitchen area. Much the same result occurs as in the case of natural draft. The grease solidifies on the walls of the stack and cold objects above or near the range, thereby turning the entire kitchen area into a potential fire-trap, and as the grease becomes rancid it creates a most unsanitary condition.

Where an electrical suction blower is installed at the end of the kitchen stack, as it is commonly done, it is necessary to place the blower out in the open where the electric motor must be weather-proofed. It is often necessary to run long electric leads to the motor, and usually the unit is not readily accessible for service and repair. In many of such cases the restaurant owner feels that the high expense entailed is be.- yond his means, with the result that he installs equipment utilizing natural draft even though it has many disadvantages and presents a fire hazard.

It is the purpose of this invention to provide a solution to these many problems by installing in the range hood in the kitchen a complete unit comprising a suction blower and a filtering device which is adapted to remove the grease particles from the air withdrawn from the range hood.

For the purposes of this application I have elected to show herein certain forms and details of an air filter machine representative of my invention. It is to be understood, however, that the embodiment of my invention herein shown and described is for the purpose of illustration only and that therefore it is not to be regarded 'as exhaustive of the variations of the invention.

In the accompanying drawings:

Fig. 1 is a composite perspective view showing the two case portions of my improved air filter machine in disconnected relationship;

Fig. 2 is a vertical sectional view, showing the air filter machine installed in the hood of a cooking range;

Fig. 3 is a front view of the removable case within which the filter and suction blower are mounted; and

Fig. a is a side elevation of the suction blower.

Referring to the drawings the numeral I designates a substantially rectangular fixed adapter case or enclosure within which is mounted a tubular conversion member or adapter 2 for conveying evacuated air from a suction blower to a stack or flue 3 associated with the hood 4 of a cooking range. The tubular adapter may embody any suitable form, but in the particular embodiment illustrated on the drawings the lower end of the adapter is rectangular while its upper end is circular. Suitable brackets 5 bolted or otherwise suitably secured to the adapter 2 and the case I are'arranged to hold the said adapter in predetermined fixed relationship with respect to the sides of the case.

Secured as by hinge means 6 and locking clamps l to the lower end of the case I is a detachable case 8 within which a suction blower or fan housing 9 and an electrical motor I!) are mounted. Each of the hinge means 6 preferably comprises a hook element on the fixed case I which is detachably engaged by a slotted or recessed member on the detachable case 8. The hinge means 6 are preferably arranged on the forward side of the fixed and detachable cases so as to permit the detachable case to be swung downwardly and forwardly about the hinge means 6, away from the back wall A at the rear of the cooking range, when the said detachable case is to be removed for servicing. The locking clamps I are preferably arranged at the opposite sides of the cases, and each embodies a well known construction comprising a pivoted clamping ring or member operable by a lever arm and engageable with a lug on the fixed case. When the lever arms of the locking clamps I are swung downwardly to firmly engage the clamping rings with the lugs on the fixed case I, the two cases.

are secured in fixed relation. Ordinarily air cannot enter between the joined ends of the fixed and detachable cases, but if so desired a rectangular flexible gasket may be interposed between the said joined ends of the cases. The upper end of the detachable case is closed by a baifle member II having a rectangular or other suitably shaped opening l2 therein which is similar in shape to both the outlet end of the fan housing 9 and the inlet end of the adapter 2. The outlet end of the fan housing 9 is preferably attached to the bafile member Ii at the opening 12 by means of a flexible canvas or neoprene connection IS. The discharge end of the fan housing 9 may be connected directly to the bafiie member II at points where the opening I2 is located, but by having the flexible connection I3 interposed between the fan housing and the baflle member there is less chance of vibration and noise developing when the fan is in operation. The inlet end of the adapter 2 is normally posi tioned in registry with the opening I2 of the baffle I I.

Mounted in the fan housing 9 is a suitable rotatable bladed rotor or fan M which is axially mounted between end openings I in the housing. The fan I4 is adapted to draw air into the housing 9 through the end openings I5 and discharge it through the connection l3 and the tubular adapter 2 into the stack 3. Secured to the shaft or the axis of the fan I4 is a pulley I6 which is connected by an endless belt I! to a drive pulley l8 secured to the shaft of the electric motor I0. The fan housing 9 and the electric motor Ill are secured by bolts or the like to frame members I9 which are welded or otherwise suitably secured to the rear side of the detachable case 8. The bafiie member I I encloses the upper side of the detachable case 8 and prevents air from being drawn downwardly into the said case when the fan or blower I4 is in operation.

The front side of the detachable case 8 is provided with a large rectangular or other suitably shaped opening 29 which is normally closed by a porous viscous type air filter 2I having a number of layers of graduated mesh screen material superimposed one upon another and so constructed and arranged that grease and dirt is removed from the air passing through the filter. The filter M is secured within a suitable frame 22 which snugly but removably fits inside the opening 20 in the front side of the detachable case 8. The filter 2I is positioned in an inclined plane, preferably at an angle of about forty-five degrees with respect to the horizontal, thereby making it possible for liquid grease collecting thereon to flow downwardly into a longitudinally disposed trough-like collector 23 mounted on the filter frame 22 or on the detachable case 8 beneath the lower end of the said filter. The grease collector 23 is provided with a drain cock or screw plug 2A which permits the contents of the collector to be drained therefrom at timely intervals. The filter frame 22 may be held within the opening in the front side of the case 8 by means of upstanding lugs 25 on the said case at the lower side of the said opening, and clamping members 26 engaging with the upper end of the said frame.

The drive pulley l8 secured to the shaft of the motor I9 is preferably adjustable so its pitch diameter can be altered, thus making it possible to increase or decrease the speed of rotation of the fan It in accordance with the requirements imposed by the static pressure in the flue or stack 3. The length of the stack varies with different installations, thereby requiring an increase or decrease in the speed of rotation of the fan in order to obtain the utmost in efficiency.

The air filtering machine may be readily mounted in the hood of a cooking range by securing the fixed case I to the said hood by bolts, welding or other suitable means. The adapter 2 being suitable in shape to receive the lower end of the stack or flue 3, is connected to the latter when the fixed case is secured to the range hood 4. A suitable cord or chain 2'! extending through a hole in the case 8 and connected to a control switch (not shown) associated with the electrical circuit of the motor It, provides convenient means for controlling the operation of the machine.

In operation the fan I4 draws the warm greaseladen air from the upper area of the hood 4 through the filter 2I and into the fan housing 9. The grease and dirt particles collect on the filter as the air passes therethrough, and the clean air which is thus freed of such particles is drawn into the fan housing 9 and then discharged into and through the stack 3. Ihe grease particles collecting on the filter flow downwardly into the collector 23. The filter 2| may be cleaned or replaced whenever required, and should the fan or motor need servicing the detachable case 3 may be removed from the fixed case I by detaching the connected parts of the hinge means 6 and the locking clamps "I.

What I claim is:

1. In an air filtering machine, a tubular adapter case mounted inside an area from which impure air is to be evacuated, a tubular adapter mounted in the adapter case and having one end connected to an outlet flue, a casing detachably connected to the adapter case and having an air inlet opening, an inclined filter mounted in the air inlet opening of the casing, a grease collecting trough positioned beneath the lower end of the filter, a suction blower mounted inside the casing and having its discharge end connected to the other end of the adapter, an electric motor mounted inside the casing, and means operatively connecting the motor and the blower.

2. In an air filtering machine, a supporting adapter case mounted inside an area from which impure grease-laden air is to be evacuated, a detachable casing connected to the adapter case, the said casing having an air inlet opening in its side, a porous air filter mounted in the opening in the side of the casing and arranged in an inclined position, means supported on the casing beneath the filter for receiving liquid dropping from the filter, a suction blower mounted in the casing for drawing air into the casing through the filter, the said suction blower having air discharge means connected to a flue, whereby air drawn into the casing may be discharged into the flue, and an electric motor mounted in the casin and operatively connected to the blower.

3. In an air filtering machine, a supporting structure secured to and positioned within a hood of a kitchen range, a casing removably suspended from the supporting structure, the said casing having an air inlet opening in one side and an air outlet opening at another side, a tubular adapter means mounted in the supporting structure and arranged in connecting relation with the outlet opening of the casing and a flue, a porous air filter removably mounted in an inclined position in the inlet opening, means supported on the casing beneath the filter for receiving liquid dropping from the filter, and a suction blower mounted in the casing and arranged to draw air into the casing through the filter and discharge it through the outlet opening.

4. In an air filtering machine, a fixed upper adapter case, a tubular adapter mounted in the fixed adapter case and arranged with one end connected to a flue, a detachable casing removably attached to the fixed case and having an air inlet opening at one side and a bafile member closing its upper end, the said baflie member having an air outlet opening to which the other end of the adapter is connected, an air filter mounted in the inlet opening of the detachable casing, and a, suction blower mounted in the detachable casing and arranged to draw air into the detachable casing through the filter and discharge it through the air outlet opening of the baflie member.

5. An air filtering machine comprising a fixed upper adapter case mounted in a suspended position inside a range hood, a tubular adapter mounted in the fixed adapter case and arranged with one of its ends connected to a flue, a, removable casing attached at its upper end to the lower end of the fixed casing and having an air inlet opening in one of its sides and a battle memher closing its upper end, the said bafile member having an air outlet opening to which the other end of the adapter is detachably connected, an inclined porous air filter arranged in the inlet opening of the detachable casing, a suction blower mounted in the detachable casing and arranged to draw air into the detachable casing through the filter and discharge it through the air outlet opening of the baflie member, and a liquid collecting trough mounted beneath the lower end of the filter.

6. In an air filtering machine for use in withdrawing grease laden air from an area within a hood above a kitchen range and discharging it through an outlet flue, a fixed adapter case mounted in a range hood above a kitchen range, a casing hingedly connected to and supported in a suspended position beneath the adapter case, the said casing having an air outlet opening at its upper side and an air inlet opening at another side, a porous air filter positioned in the air inlet opening of the casing, a suction blower mounted in the casing and having one or more air inlet openings in communication with the interior of the casing and air discharge means connected to the air outletopening of the casing, and a tubular adapter connecting the air outlet opening of the casing with an outlet flue.

DALLAS HURD GRAY, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,502,844 Bingman July 29, 1924 1,862,659 Christofierson June 14, 1932 2,008,540 Berry July 16, 1935 2,121,278 Babcock June 21, 1938 2,187,019 De Mund et a1 Jan. 16, 1940 2,355,963 Ponselle Dec. 7, 1943 2,356,757 Fleisher Aug. 29, 1944 2,369,375 Sonntag Feb. 13, 1945 

